The present invention relates in general to radio frequency shielding and in particular to various embodiments of shielding for portable electronic devices such as contactless smartcards.
Generally, portable electronic devices such as contactless smartcards, key fobs, radio frequency identification devices (RFID), cellular phones, etc. are designed to provide the consumer a way to engage in wireless communication and data exchange using radio frequency (RF) signals. For example, contactless smartcards allow a consumer to store and transmit financial data and other personal data to third parties such as banks. In another example, portable electronic devices such as RFIDs are used to wirelessly identify articles and allow monitoring of such articles during manufacturing, shipment, storage, etc. Due to the increased popularity of smartcards and RFIDs, it is envisioned that they will eventually be used for virtually all transactions involved in banking, health, insurance, social security, tracking, shipping, etc.
Because contactless electronic devices can operate without wires, contactless portable electronic devices are expected to replace other types of devices that require physical contact and/or physical connections to communicate with other devices and systems. Illustratively, contactless smartcards are expected to replace regular credit cards, as they need not be in contact with a transaction terminal to be operated. Regular contact credit cards having magnetic strips and contact smartcards must come in contact with a reader. Similarly, RFIDs are expected to replace many of the bar code reading systems due to the fact that articles may be identified and tracked wirelessly.
A major benefit of contactless portable electronic devices is that they do not have to be removed from a user's wallet, briefcase, backpack, or purse to be used. Currently, an international standard has been established that sets a standard range between a contactless reader and the contactless portable electronic device. Therefore, a contactless portable electronic device may wirelessly exchange data with a contactless reader without the user having to remove the contactless portable electronic device from his wallet, purse, pocket, etc. as long as he is in range of the contactless reader. For simplicity and cost savings, contactless portable electronic devices often do not have embedded power sources (i.e., batteries). For example, smartcards and RFIDs have an antenna designed to receive RF signals from the contactless reader that is used to both power the smartcard/RFID devices, as well as enable them to communicate with the contactless reader.
Unfortunately, due to the wireless nature of the contactless portable electronic devices, it is entirely possible that a contactless reader may be used for surreptitious interrogation (e.g., data skimming) of the contactless portable electronic devices. In addition, it is conceivable that a contactless reader may be developed or modified to generate a much greater RF signal strength and sensitivity and thereby increase the standard range. Such an enhanced reader may allow surreptitious interrogation of the contactless portable electronic devices from a greater range.
Some have proposed using a passive electromagnetic shield to prevent surreptitious interrogation. One particular reference that describes creating a passive electromagnetic shield is U.S. Pat. No. 6,121,544 issued to Petsinger (herein Petsinger). Petsinger discloses an electromagnetic shield device that is used to shield contactless smartcards and RFIDs from electromagnetic energy. Petsinger teaches a specialized enclosure that is made of a soft magnetic alloy with a very high initial and maximum magnetic permeability. The enclosure is hydrogen annealed to provide magnetic shielding properties. Petsinger also discloses that the relatively high intrinsic electrical conductivity of the magnetic shielding simulates a Faraday cage to protect the contactless smartcards/RFIDs from electric fields as well. Unfortunately, the electromagnetic shield as taught by Petsinger is a complicated multifaceted device that is expensive to manufacture and requires that the smartcard/RFID be completely enclosed by magnetic materials.
The device in Petsinger also appears to be rigid in structure. The rigidity of Petsinger's device may make the device undesirable for use in a person's wallet, since a person's wallet is continually subjected to varying forces when it is in a person's pocket. The rigid device may break or crack when subjected to such forces.
Therefore, what is needed is a shielding device and method that shields the contactless portable electronic devices from unauthorized interrogation that is simple to use and is cost effective.